Abstract: Analysis of the differences in antioxidant properties of Poa pratensis Linn. after spraying exogenous myo-inositol (MI) can provide a theoretical basis for improving drought tolerance of Poa pratensis L. In this study,‘Kentucky’,a variety of Poa pratensis L.,was used as the material. After 40 days of seedling emergence,5 concentrations of MI solution were sprayed on the leaves,respectively,and the soil was subjected to natural water loss and drought stress after 5 days of spraying MI. The physiological indexes such as phenotype,chlorophyll content,hydrogen peroxide content and antioxidant system enzyme activity of plants treated with different concentrations of MI solution were observed under 6 drought stress times. The drought tolerance of Poa pratensis L. after MI treatment was evaluated by principal component analysis,correlation analysis and membership function. It was found that spraying MI could slow down the degradation of chlorophyll content,reduce the production of oxygen radicals and the accumulation of malondialdehyde,and increase the activity of antioxidant enzyme system. Correlation analysis showed that chlorophyll,oxygen radical and other indicators were related to the drought resistance of Poa pratensis L. and there was a significant positive correlation between chlorophyll and oxygen radical content and antioxidant enzyme system activity. The study preliminarily determined that spraying exogenous inositol treatment could improve the drought resistance of Poa pratensis L. and the leaves showed the best drought resistance under 400 mg·L^-1 MI treatment.

Key words: Poa pratensis L., Drought stress, Myo-inositol, Activities of antioxidant enzymes

摘要： 分析草地早熟禾(Poa pratensis Linn.)经喷施外源肌醇(myo-Inositol，MI)处理后有关抗氧化特性的差异，可为提高草地早熟禾耐旱性措施提供理论依据。本研究以草地早熟禾(Poa pratensis L.)品种‘肯塔基’(Kentucky)为材料，出苗40 d后叶面喷施5个浓度MI溶液，持续5 d后进行土壤自然失水干旱胁迫，在6个干旱胁迫时间下观测不同浓度MI溶液处理后植株的表型、叶绿素含量、过氧化氢含量和抗氧化酶系统活性等生理指标，通过主成分分析、相关性分析和隶属函数评价MI处理后草地早熟禾的耐旱性。结果发现喷施MI能减缓叶绿素含量降解、减少氧自由基产生及丙二醛积累量、提高抗氧化酶系统活性；相关分析表明叶绿素、氧自由基等指标与草地早熟禾的抗旱性有关，且叶绿素与自由基含量之间、抗氧化酶系统活性之间呈显著正相关。本研究确定了草地早熟禾喷施外源肌醇处理后可提高抗旱性，其中叶片在400 mg·L^-1 MI处理下植株表现抗旱性最佳。

关键词: 草地早熟禾, 干旱胁迫, 肌醇, 抗氧化酶系统活性